Your account password is what you used when you installed CrashPlan. It is used to access the web management interface and links all your computers together.
A data password is used to prevent someone else from restoring your data.
The data password is never sent to the PRO Server, and therefore your admins cannot retrieve this password for you if you lose it.
The data remains unaffected. Imagine you have your keys to your car locked in a safe. The data password is the key to the safe, not the keys to the car. You can still restore versions of files encrypted with the original data password.
Your data is not actually encrypted with the data password or account password. Those passwords act as a way to lock or protect the actual key used to encrypt data. So if you change your password, we do not have to re-encrypt your data or start back up over. We just relock the data key with the new data password. Your data encryption key never changes.
The data password is completely independent of your account password.
Before you use this feature, we display warnings to let you know that there is absolutely no way to help you recover a password your admin is never aware of.
The only way to remedy this situation is to restart your initial backup using a new data password, because CrashPlan won't be able to decrypt the data that has already been backed up.